Microsoft is bolstering Microsoft Teams to better challenge Slack in the battle of the collaborative, chatty workplace apps. For starters, Teams will replace Skype for Business teamwork app. At the same time, Teams will get some of Skype’s advanced voice and video calling technology.

“Microsoft Teams will evolve as the core communications client,” Microsoft Office 365 Vice President Ron Markezich said at a press briefing, reports Reuters. “We will make Microsoft Teams the hero and primary experience for all voice, video, and meetings.”

The Teams app is included in Microsoft’s Office 365 software bundle, which includes legacy programs like Word and PowerPoint. This subscription pool is vast. As of April 2017, Microsoft said it had over 100 million Office 365 subscribers, giving the company a huge competitive advantage over Slack. Any business that already subscribes to Office 365 may have no interest in taking on an additional subscription — especially when Microsoft Teams already closely mimics Slack’s chat-friendly interface.

At its Frontiers event this month, Slack reported it currently has over 50,000 teams that pay for its service, and marked the first day it had over six million users logged into the service in a 24-hour period. Meanwhile, Microsoft says that over 125,000 organizations currently use its Teams app.

For over a year, Slack has been candid about how it intends to compete with Microsoft, which Slack feels copied many of its chat features. Before Microsoft announced Teams in late 2016, Slack purchased a full page in The New York Times, extolling its deep research into and understanding of how people and workplaces now communicate over software mediums. Slack addressed Microsoft directly:

“How far you go in helping companies truly transform to take advantage of this shift in working is even more important than the individual software features you are duplicating.”

Praveen Kumar is a passionate blogger, Entrepreneur & digital marketer from India. He is founder of TheinNews, Pintire, Seotools360. At TheinNews he mostly writes about How to tips, Tech news,Gadgets news, products reviews etc.